Refactoring. Moved shared code into separate functions.
Added edit action for DNS module's CLI mode. Hostname editing supported.
Updated changelog.

Conflicts:

	VERSION
	package/yast2-network.changes

Conflicts:

	VERSION
	package/yast2-network.changes
Refactoring DNS. Added setters which are mainly used by CLI.
DNS CLI supports editing nameservers.
Updated changelog.

Conflicts:

	VERSION
	package/yast2-network.changes

Conflicts:

	VERSION
	package/yast2-network.changes

Conflicts:

	package/yast2-network.changes